INTRODUCTION AND DEFINITIONS
According to the 2007 Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II), acute limb ischemia is defined as a sudden decrease in limb perfusion that causes a potential threat to limb viability (manifested by ischemic rest pain, ischemic ulcers, and/or gangrene) . Patients who present later than two weeks after the onset of the acute event are considered to have chronic limb ischemia.
The management of acute arterial occlusion remains a challenge for vascular specialists. Surgical thromboembolectomy and bypass grafting were the mainstays of therapy for many years . Subsequently, thrombolytic therapy and percutaneous transluminal angioplasty (PTA) have become treatment options for selected patients [3,4].
Despite these advances, the morbidity, mortality, and limb loss rates from acute lower extremity ischemia remain high . Thus, regardless of the treatment modality used, early diagnosis and rapid initiation of therapy are essential in order to salvage the ischemic extremity.
The major causes of and management approaches to acute limb ischemia will be reviewed here. Issues related to chronic limb ischemia (ie, similar manifestations in patients who present more than two weeks after symptom onset) are discussed separately. (See "Treatment of chronic lower extremity critical limb ischemia".)
Acute arterial occlusion can be the result of an embolus from a proximal source lodging into a more distal vessel, acute thrombosis of a previously patent artery, acute thrombosis of a stent or graft, and dissection of an artery or direct trauma to an artery. Common etiologies for each of these mechanisms are presented in the table (table 1).